When do i start putting my baby in the direct sunlight to help her with vitamin d and to prevent rickets?

Be careful: You are correct that the ultra violet b rays of sunlight start the production of vit d in our skin...But there are risks as well...An increase in skin cancer and melanoma. Dermatologists would probably answer..."never". My answer is do it prudently and be aware clothing and sunscreen block ultravilet b rays. The national recommendation is to supplement all infants with 400 iu of vit d daily.